1. Field of the Invention
The present invention relates to an image forming apparatus such as copiers, printers and facsimiles, and to an image forming process thereof. Particularly, the invention relates to an image forming apparatus including: a development unit for forming a toner image on an image carrier by supplying, by means of a developer carrier, a toner contained in a developer reservoir to a latent image formed on the image carrier; a transfer unit for transferring the toner image formed on the image carrier onto a transfer medium; and a recovery unit for recovering the toner remaining on the image carrier after image transfer.
2. Description of the Related Art
In the conventional image forming apparatuses such as copiers, printers and facsimiles, a development unit adapted to form the toner image in the following manner has been widely used for developing the latent image formed on the image carrier. That is, the toner contained in the developer reservoir is fed to the developer carrier, while the toner thus fed to the developer carrier is regulated by a regulator member. Subsequently, the toner is supplied from the developer carrier to the latent image formed on the image carrier, thereby to form the toner image on the image carrier.
Subsequently, the toner image thus formed on the image carrier is transferred onto the transfer medium by means of the transfer unit. On the other hand, the toner remaining on the image carrier after image transfer is recovered by means of the recovery unit employing a cleaning blade or the like.
In the conventional practice, a recover toner thus recovered by the recovery unit is transported by a transport unit to a waste toner container disposed in the image forming apparatus. Thus, the recover toner is stored in the waste toner container.
Unfortunately, the following problem exists in the above case where the recover toner thus recovered by the recovery unit is stored in the waste toner container disposed in the image forming apparatus. That is, a space to install the waste toner container must be spared in the image forming apparatus, so that the dimensions of the image forming apparatus are increased accordingly. This makes it impossible to meet a recent demand for the downsizing of the image forming apparatus.
Furthermore, another problem is encountered in the above arrangement wherein the recover toner recovered by the recovery unit is stored in the waste toner container. The recover toner is gradually accumulated in the waste toner container, which will become full in the end. If the image forming operation is still further carried on, the recover toner will brim over the waste toner container, so as to be scattered in an interior of the image forming apparatus. Hence, the interior of the image forming apparatus is contaminated with the toner, so that harmful influences are exerted on formed images. This requires a bothersome task to replace the waste toner container at a proper time.
There has been proposed a prior-art apparatus wherein the recover toner thus recovered by the recovery unit is returned by a return unit to the developer reservoir of the development unit so that the recover toner is admixed with the toner contained in the developer reservoir and used again for development.
However, the recover toner is deteriorated as combined with foreign substances such as a filler during the transfer process. In a case where such a recover toner is admixed with the toner contained in the developer reservoir and used again for development, the formed images may be adversely affected.
Still another prior-art apparatus has been proposed wherein a deformable partitioning member is disposed in the developer reservoir of the development unit, such as to partition the developer reservoir into a toner container for containing therein the normal toner and a waste toner container for storing the recover toner. Thus, the recover toner recovered by the recovery unit in the aforementioned manner is returned into the waste toner container by means of the return unit, whereby the recover toner is prevented from being used again for development (Japanese Unexamined Patent Publication No. H05-088549).
However, it is a cumbersome task to mount the deformable partitioning member in the developer reservoir. In addition, an increased cost results.